Deposition-etch-deposition (DED) has been demonstrated to fill high aspect ratio vias, holes, and trenches. The DED method encounters gap fill limitations when utilized to fill features with increased reentrancy below the top of the structure. Structures that have a largely reentrant feature compared with the opening dimension or any large reentrant feature compared to the bulk opening do not allow enough material to be grown in the line of sight of the ions for the etch before the features pinch off.
It is in this context that implementations of the disclosure arise.